This invention relates to vehicle components incorporating polymeric elements with members, casings or gaskets formed thereon and, more particularly, to vehicle component assemblies including vehicle exterior lighting assemblies such as a composite headlamp assembly incorporating a hard coated polycarbonate lens element bonded to a molded polymeric gasket.
In recent years, vehicle headlamp assembly designs have been driven by body styling demands. The lenses of the newer headlamp assemblies are more contoured so that they follow the contours of the vehicle body. Traditional headlamp assemblies typically included a stainless steel bezel which permitted the lens to be mounted in an opening in the vehicle body. More recently, headlamp assemblies include a preformed gasket which is subsequently attached, for example by an adhesive to the peripheral portion of the lens, which permits the lens to be fitted more closely with the body of the vehicle. Such preformed gaskets are, however, difficult to tool and, in some cases, their installation is difficult and labor intensive. Moreover, conventional lenses are now typically molded from a polycarbonate resin. Since polycarbonate lenses are vulnerable to abrasion from road debris and the elements and to discoloration from ultraviolet radiation, the lenses are coated with a hard coat to provide a durable outer surface which is resistant to scratching and which protects the polycarbonate lens from ultraviolet radiation. Heretofore, these hard coatings have inhibited adequate adhesion between the preformed gasket material and the lens. Consequently, in order to improve the adhesion of the gasket to the lens, some conventional gaskets and lenses include structures to provide mechanical interlocking of the gasket to the lens to supplement the bond provided by the adhesive.
Referring to FIGS. 14A and 14B, one conventional, prior known polycarbonate lens (100) includes a first slotted groove (102) along its peripheral edge (104) to provide an anchorage for a conventional preformed gasket (106), as will be more fully described below, a second slotted groove (108) along its peripheral edge for aligning and holding the gasket while it is installed on the lens, and a projecting flange (110), which also assists in the alignment and retention of the gasket (106) on the lens during the installation process. As a result, the molding apparatus for the lens requires complicated tooling, and the lenses are subject to tight tolerances.
The preformed gasket (106) includes corresponding structures that interlock with the lens grooves and flange. To install the gasket, an adhesive is applied to the gasket or lens perimeter, and a first end (112) of the gasket is seated in the first slotted groove (102) to anchor one end of the gasket (106) while the gasket is stretched around the perimeter of the lens. As the gasket is stretched around the perimeter, an intermediate portion of the gasket is then seated in the second slotted groove (108) to align the gasket and provide further mechanical interlocking of the gasket to the lens. Then the second of end (114) of the gasket is wrapped around the perimeter of the lens and seated in the first slotted groove (102) adjacent the first end of the gasket such that the gasket ends define a break or space 115 (FIG. 14A). In this manner, these grooves and flange of the lens and corresponding structures on the gasket cooperate to align the gasket and to mechanically retain the gasket on the lens while the adhesive cures and provide mechanical interlocking of the gasket to the lens. Such process is often difficult and time consuming. Also, the retention of the gasket on the lens is sometimes less than adequate, as is the adhesion between the gasket and lens. While these gaskets have improved the fit-up of the headlamp assembly with the contoured vehicle body, the apparatus used to form these gaskets is also difficult and expensive to tool.
Further, gaskets (106) may be formed with retainers or tabs (116). The retainers (116) project from the gasket and secure to a housing by fasteners to provide a means for temporarily securing the lens and the gasket to the housing during installation. These retainers further complicate the molding process of the gasket. In some applications, the gasket is molded from two materials, with the second material forming the retainers having a greater durometer hardness to increase the stiffness of the gasket where the retainers project from the gasket. Again, this process increases the cost of the gasket and is also difficult to tool.
Despite the improved fit up, these preformed gaskets may not provide the desired life expectancy and may require reinstallation or replacement. Furthermore, because of the geometry of the gasket, there may also be a gap between the first and second ends of the gasket such as that shown at 115 in FIG. 14A. This gap may affect the aerodynamics of the vehicle body or the wind noise of the assembly. Moreover, installation of these preformed gaskets is labor intensive, requiring manual manipulation of the gasket around the lens. This manual manipulation may lead to worker fatigue and, ultimately, may increase the number of defective installations and the cost of the vehicle.
Consequently, there is a need for vehicle component assemblies which incorporate resinous elements, especially hard coated polycarbonate lenses of vehicle headlamp assemblies, and cooperating gaskets or molded members which will exhibit improved adhesion between the gasket or molded member and the resinous element. Moreover, there is a need for such assemblies which can be manufactured and installed with significantly reduced labor, time, and costs.
Accordingly, the present invention provides a vehicle component assembly such as a modular headlamp assembly which is ready for installation virtually entirely from the exterior of a vehicle or other supporting body in a manner which is heretofore been unknown. The headlamp assembly combines an optical element, typically formed of a polymeric material, such as a polycarbonate material, which has been shaped and coated with a protective coating to be ready for application in a headlamp assembly of a vehicle, and a flexible, resilient gasket which is integrally molded onto the perimeter of the optical element to provide a cover for the gap between the optical element and the opening of the vehicle body. The invention therefore eliminates the need for piecemeal assembly of the optical element and gasket of the headlamp assembly, while also providing a secure bond of the gasket material to the hard coated polycarbonate optical element to form a lens module, all in a molding process in a manner heretofore unknown.
According to one aspect of the invention, an optical component of a vehicle comprises an optical element having a peripheral portion and a gasket. The peripheral portion includes inner and outer peripheral side surfaces and a peripheral edge surface. The optical element includes a protective coating on at least one of the inner peripheral side surface, the outer peripheral side surface, and the peripheral edge surface, and a primer coating over at least a portion of the protective coating. The gasket is integrally molded on at least a portion of the primed portion on at least one of the inner peripheral side surface, the outer peripheral side surface, and the peripheral edge surface of the optical element. The gasket is thus bonded to at least a portion of the primed area of the optical element and includes extending portions at positions spaced from the optical element adapted to cover a gap between the optical element and the vehicle body.
In one form, the optical element comprises a polymeric optical element, such as a polycarbonate optical element. Furthermore, the optical element may comprise a lens, such as a headlamp lens. Preferably, the headlamp lens has a contoured surface wherein the contoured surface follows the contour of the body of the vehicle. The peripheral portion of the lens may include at least one cooperating structure, for example a groove which extends around at least a portion of the lens, a through-hole, or a lip, which provides mechanical interlocking of the gasket and the lens. In other aspects, a conventional lens element may be used, which typically includes one or more grooves extending into the peripheral edge surface of the lens.
In another form, the gasket material may comprise a melt-processible gasket material or a non melt-processible gasket material. For example, as suitable melt-processible material includes polyvinyl chloride, styrene/butadiene/styrene (SBS) elastomers, styrene/ethylene/butadiene/styrene (SEBS) elastomers, copolyester elastomers, polyether blockamides, and thermoplastic urethane. Other suitable melt-processible gasket materials include cross-linked materials, for example styrene butadiene rubber (SBR) elastomer, ethylene propylene diene terpolymer (EPDM) elastomer, and ethylene propylene copolymer (EPM) elastomer. Suitable non melt-processible gasket materials include thermosetting reaction injection molded urethanes. Preferably, the gasket material has a hardness in a range of about 40 to 100 Shore A durometer. More preferably, the gasket material has a hardness in a range of about 55 to 100 Shore A durometer. Most preferably, the gasket material has a hardness in a range of about 65 to 85 Shore A durometer.
In yet further aspects, the protective coating comprises an organic hard coat, such as silicone, an inorganic hard coat, such as transition metal compounds, or an organic/inorganic hybrid hard coat, such as organic modified inorganics, for example a silicone modified silicon dioxide, which is applied to at least the outer, exposed surface of the optical element and protects the optical element from abrasion. Suitable inorganic hard coats include, for example, metal oxides, and metal nitrides. For example, metal oxides, such as silicon dioxide, may be used.
In another form, the optical component preferably includes ultraviolet radiation absorbers to protect the polycarbonate material from radiation damage, which are incorporated into the optical element and/or the protective coating. The ultraviolet radiation absorbers may be incorporated into an intermediate primer coating, which is applied to the optical element to improve the adhesion between the hard coating and the optical element.
According to another aspect of the invention, a vehicle lighting assembly includes a housing adapted for mounting in the body of a vehicle and a lens module mounted to the housing. The lens module includes a lens and a protective coating on at least an exterior surface of said lens, and a primer coating over at least a portion the protective coating. The lens module further includes a gasket integrally molded on at least a portion of the primed area and is adapted to cover a gap between the lens and the body of the vehicle. The gasket material preferably comprises either a melt-processible gasket material or a non melt-processible gasket material.
In one form, the lens module is secured to the housing, for example by ultrasonic welding or mechanical attachment, to provide a water tight seal between the lens module and the housing, which eliminates the need for forming or providing retainers on the gasket.
According to a further aspect, a vehicle component assembly includes a polymeric body having a protective coating thereon and at least one primer coating overlaying at least a portion of the protective coating. A member is integrally molded onto at least a portion of the primer coating, with the molded member extending away from the polymeric body adapted to extend between the body and the vehicle.
According to yet another aspect, a method of attaching a molded member to a polymeric vehicle element includes providing a polymeric vehicle element, applying a primer to a predetermined area of the element, and forming an integrally molded member on at least a portion of the predetermined area from a polymeric material. The vehicle element includes a protective coating to protect the vehicle element from abrasion and, preferably, ultraviolet absorbers to protect the vehicle element from ultraviolet radiation degradation.
In one aspect, the molded member is formed by injection molding a gasket material onto the vehicle element. Injection molding may include reaction injection molding the member onto the vehicle element. Preferably, the primer is applied to a peripheral portion of the vehicle element to improve the adhesion between the molded member and the vehicle element. More preferably, the vehicle element is primed with a first primer and then the first primer is primed with a second primer. The first primer is provided to increase the adhesion between the protective coated vehicle element and the second primer which, in turn, is adhered to the molded member.
In other aspects, the method further includes preheating the vehicle element, for example by applying warm air to the vehicle element. By preheating the vehicle element, the time for the primer or primers to flash is reduced, and the moldability of the part is improved.
The vehicle components and/or lighting assemblies of the present invention overcome the differences of curvature and dimensions between the vehicle element and the body panels of a vehicle by providing a resilient gasket or member formed on the element preferably by molding. The vehicle is preferably a polycarbonate element with a protective coating and protect the element from abrasion and, preferably, includes ultraviolet radiation absorbers to protect the element from ultraviolet radiation damage. The primer coating increases the adhesion between the molded gasket or member and the protective coated element in a manner that provides superior adhesion characteristics heretofore unknown. Moreover, by molding the gasket or member onto the vehicle element, the assembly and installation time is significantly reduced thereby saving costs.